1. Field of the Invention
The invention relates to a method for mobile radio communication between a communication partner device and an in particular mobile communication device, and also a mobile communication device, configured to carry out the method, wherein one of the communication devices is the calling communication device and the other of the communication devices is the receiving communication device. In other words, both the communication partner device and the mobile communication device can be the calling or the receiving communication device.
In order to carry out the method, at least the in particular mobile communication device, i.e., for example, a mobile radio telephone, is equipped according to the invention for audio communication with at least two communication facilities for setting up different mobile radio connections. In the proposed method, a communication is conducted at least temporarily, for example during the connection set-up and/or with decreasing reception quality, or permanently, via at least two mobile radio connections in at least two different mobile radio networks, wherein the reception quality of the receive signals of each mobile radio connection is evaluated in the mobile communication device and the mobile radio connection with the best reception quality is selected for the mobile radio communication, at least in the receiving direction. The communication facility is a transmit and receive facility for a mobile communication, in particular for setting up mobile radio connections by means of a SIM card, via which the connection is set up to the mobile radio provider via the latter's mobile radio network. Here, a communication facility in each case has its own mobile radio number on which the device can be contacted.
2. Related Art
Mobile radio telephones are already known which can accommodate two SIM cards, wherein the user, before making a call, can select which SIM card is chosen with which telephone number for a call. This is used, for example, if a mobile radio telephone is used as both a company telephone and a private telephone, so that the user, before each call, can choose the account to which or the telephone number on which the call is to be booked. However, mobile telephones of this type cannot usually set up two different mobile radio connections simultaneously.
A problem with mobile radio telephone calls consists in disconnected or disturbed connections between two mobile communication partners or one mobile communication partner and one non-mobile communication partner, for example due to the occurrence of radio holes which, even today, are still an everyday occurrence. No mobile radio provider can currently offer blanket mobile radio coverage. Many disturbances of the reception situation result in disconnection of an existing mobile radio connection and require a re-establishment of the mobile radio connection, possibly during an automobile journey.
Most mobile radio telephones available on the market have only one SIM card and one communication facility. A disconnected connection triggered by deterioration of the reception situation can then be restored only by the re-establishment of the connection, but this is usually successful only if the reception situation of the mobile radio device has been improved, for example through a change of location.
In the known mobile telephones with two SIM cards, the user can switch over manually between two mobile radio providers, insofar as the SIM cards inserted into the mobile radio telephone originate from different providers. Since the network coverage at a given location is typically different for different providers, a changeover of provider following a disconnected connection can often result in an improved speech quality. However, it is very annoying for the user that the connection is first disconnected and a re-establishment of the call then has to be initiated manually.
EP 0 695 104 B1 describes a method for transferring a telephone call made on a mobile telephone from a first mobile communication connection to a second mobile communication connection if the first mobile communication connection is disconnected because, for example, the quality of the connection has deteriorated to the extent that a disconnection of the first mobile communication threatens. To do this, the mobile telephone has two different communication systems which can set up the first and the second communication connection in parallel. This is carried out on request by a remote communication center, which initiates a conference call circuit with which the mobile telephone can be called simultaneously on the first and the second communication connection, so that the better of the two communication connections can be selected. However, this requires that the mobile radio provider offers corresponding technical facilities, which are usually available only in comparatively expensive tariffs.
From DE 101 33 590 A1, a method is known for switching over between a plurality of SIM cards in a mobile telephone, in which a service provider identification number is allocated to a SIM card, and the mobile telephone, on receiving such a service provider identification number, switches over to the SIM card allocated to the latter, for example if, during a journey abroad, a corresponding different service provider is available.